Quantum information articles within Nature Communications

Featured

  • Article |

    Quantum annealing is the quantum computational equivalent of the classical approach to solving optimization problems known as simulated annealing. Boixo et al.report experimental evidence for the realization of quantum annealing processes that are unexpectedly robust against noise and imperfections.

    • Sergio Boixo
    • , Tameem Albash
    •  & Daniel A. Lidar

  • Article |

    Future quantum computers need quantum memories that store arbitrary states for long periods, without incurring significant access latencies. Using high-order dynamical decoupling sequences, this work shows a practical scheme to suppress physical errors and guarantee high-fidelity storage for long times.

    • Kaveh Khodjasteh
    • , Jarrah Sastrawan
    •  & Lorenza Viola

  • Article |

    The spin of an electron bound to a single phosphorus atom in silicon is of interest for spin-based electronics such as quantum computing. Here, Büch et al. show these spin properties are retained even for clusters of a few phosphorus atoms, providing an additional means for quantum bit addressability.

    • H. Büch
    • , S. Mahapatra
    •  & M. Y. Simmons

  • Article |

    Superconducting circuits may be useful as quantum simulators, but new tools are needed to fully characterize their behaviour. Shankset al.present a scanning transmon qubit, map its coupling strength to a separate resonator, and propose its use to probe photon number in a superconducting resonator lattice.

    • W. E. Shanks
    • , D. L. Underwood
    •  & A. A. Houck

  • Article |

    Quantum annealing is one strategy that may enable quantum computations that are robust to noise, despite the system’s interaction with the environment. Dickson et al. explore quantum annealing for a 16-qubit system and find that for a small energy-gap avoided crossing, it can be robust against thermal noise.

    • N G Dickson
    • , M W Johnson
    •  & G Rose

  • Article |

    High-quality narrow bandwidth single-photon states with tunable frequency are essential for quantum and atomic technologies. Using a whispering gallery mode resonator, Förtsch et al. build such a source with wavelength tuning across 100 nm and controllable narrow bandwidth.

    • Michael Förtsch
    • , Josef U. Fürst
    •  & Christoph Marquardt

  • Article |

    Nitrogen-vacancy centres in diamond are a promising route for solid-state quantum information processing and magnetometry, but longer coherence times are needed to optimize protocols. Here, Bar-Gill et al. suppress decoherence to realize nitrogen-vacancy spin coherence times approaching one second.

    • N. Bar-Gill
    • , L.M. Pham
    •  & R.L. Walsworth

  • Article
    | Open Access

    Controlling coupling between distant quantum objects is important for implementation of quantum technologies. Providing an important step towards using semiconductor structures for hosting optically controlled qubits, this work shows coherent coupling between three quantum dot excitons via a cavity.

    • F. Albert
    • , K. Sivalertporn
    •  & W. Langbein

  • Article |

    Non-Abelian anyons are exotic quasiparticles envisioned to be promising candidates for solid-state quantum computation. Clarkeet al. propose a device fabricated from fractional quantum Hall states and superconductors that supports a new type of non-Abelian defect that binds parafermionic zero modes.

    • David J. Clarke
    • , Jason Alicea
    •  & Kirill Shtengel

  • Article |

    In quantum communication, the noisy-storage model assumes that an attacker’s memory device is imperfect, thus enabling two parties to implement protocols securely. Using polarization-entangled photon pairs, Ng et al.analyse and verify a two-party bit commitment protocol within the noisy-storage.

    • Nelly Huei Ying Ng
    • , Siddarth K. Joshi
    •  & Stephanie Wehner

  • Article |

    Continuous variable quantum key distribution allows secure communication that is more robust against channel losses than discrete approaches, yet is strongly affected by noise. Madsenet al.devise a continuous scheme for modulated entangled states that is more tolerant to noise and loss than other protocols.

    • Lars S. Madsen
    • , Vladyslav C. Usenko
    •  & Ulrik L. Andersen

  • Article
    | Open Access

    Blind quantum computation is a protocol that permits an algorithm, its input and output to be kept secret from the owner of the computational resource doing the calculation. Morimae and Fujii propose a strategy for topologically protected fault-tolerant blind quantum computation that is robust to environmental noise.

    • Tomoyuki Morimae
    •  & Keisuke Fujii

  • Article
    | Open Access

    Multi-partite entanglement is essential not only to understand large quantum ensembles but also to build useful quantum technologies. Armstronget al. demonstrate multimode entanglement of up to eight modes using programmable virtual networks based on linear optics that can be switched in real time.

    • Seiji Armstrong
    • , Jean-François Morizur
    •  & Hans-A. Bachor

  • Article |

    Precise qubit manipulation is essential in quantum computation; however errors can occur from fluctuations in the magnetic field. Wanget al. propose a robust scheme for universal control of qubits in a semiconductor double quantum dot, cancelling leading orders of error in field gradient variation.

    • Xin Wang
    • , Lev S. Bishop
    •  & S. Das Sarma

  • Article
    | Open Access

    Quantum communication promises important advances in information and communication technology, yet it suffers from alignment sensitivity. Here, an alignment-free approach is demonstrated using liquid crystal devices, allowing for broader applications, including satellites.

    • Vincenzo D'Ambrosio
    • , Eleonora Nagali
    •  & Fabio Sciarrino

  • Article |

    Geometrically frustrated spin systems are a class of statistical mechanical models that have received widespread attention, especially in condensed matter physics. This study experimentally demonstrates a quantum information processor that can simulate the behaviour of such frustrated spin system.

    • Jingfu Zhang
    • , Man-Hong Yung
    •  & Jonathan Baugh

  • Article |

    Quantum phase transitions are generally associated with many-body quantum systems undergoing changes between different phases. This study examines the connection between such phase transitions and quantum information processing, and finds that different quantum phases can have different computational power.

    • Jian Cui
    • , Mile Gu
    •  & Vlatko Vedral

  • Article |

    Electron spins at nitrogen-vacancy centres in diamond are thought to be the most promising building blocks for practical realizations of quantum computers. Yaoet al. present a scalable architecture for a quantum information processor based on such vacancy centres that operates at room temperature.

    • N.Y. Yao
    • , L. Jiang
    •  & M.D. Lukin

  • Article
    | Open Access

    Single-photon sources are important for quantum optical technologies, although achieving efficient light extraction from them with waveguides is limited in top-down approaches. Reimeret al. show a high extraction efficiency using a bottom-up method to grow quantum dots on the axis of nanowire waveguides.

    • Michael E. Reimer
    • , Gabriele Bulgarini
    •  & Val Zwiller

  • Article
    | Open Access

    Point defects in diamond in the form of nitrogen vacancy centres are believed to be promising candidates for qubits in quantum computers. Grotzet al. present a method for manipulating the charge state of nitrogen vacancies using an electrolytic gate electrode.

    • Bernhard Grotz
    • , Moritz V. Hauf
    •  & Jose A. Garrido

  • Article
    | Open Access

    Although they offer significant promise, practical implementations of quantum key distribution are often not as rigorous as theory predicts. This study demonstrates how two instances of such discrepancies can be resolved by taking advantage of an enotropic formulation of the uncertainty principle.

    • Marco Tomamichel
    • , Charles Ci Wen Lim
    •  & Renato Renner

  • Article
    | Open Access

    When two spatially separated parties flip a coin, it is impossible to choose between two alternatives in an unbiased manner. This study presents a quantum coin-flipping protocol that overcomes this problem and ensures a dishonest party cannot bias the outcome completely.

    • Guido Berlín
    • , Gilles Brassard
    •  & Wolfgang Tittel

  • Article |

    Generation of multipartite entanglement between quantum states is crucial for developing quantum computation systems, although it has proven harder to achieve for photons than ions. Here, an eight-photon entangled state based on four independent photon pairs is observed, beating the previous record of six.

    • Yun-Feng Huang
    • , Bi-Heng Liu
    •  & Guang-Can Guo

  • Article
    | Open Access

    Most quantum communication experiments are performed at visible wavelengths, yet practical, long-range schemes need photons in the telecommunications range. Here, down-conversion of a visible photon to the near-infrared is demonstrated, while retaining its entanglement to another visible photon.

    • Rikizo Ikuta
    • , Yoshiaki Kusaka
    •  & Nobuyuki Imoto

  • Article
    | Open Access

    Quantum computing has advantages over conventional computing, but the complexity of quantum algorithms creates technological challenges. Here, an architecture-independent technique, that simplifies adding control qubits to arbitrary quantum operations, is developed and demonstrated.

    • Xiao-Qi Zhou
    • , Timothy C. Ralph
    •  & Jeremy L. O'Brien

  • Article |

    A quantum simulator can follow the evolution of a prescribed model, whose behaviour may be difficult to determine. Here, the emergence of magnetism is simulated by implementing a quantum Ising model, providing a benchmark for simulations in larger systems.

    • R. Islam
    • , E.E. Edwards
    •  & C. Monroe

  • Article
    | Open Access

    Two-qubit operation is an essential part of quantum computation, but implementation has been difficult. Gotoet al.introduce optically controllable internuclear coupling in semiconductors providing a simple way of switching inter-qubit couplings in semiconductor-based quantum computers.

    • Atsushi Goto
    • , Shinobu Ohki
    •  & Tadashi Shimizu

  • Article |

    A quantum key distribution system allows two remote parties to communicate in secret by a shared key code. This work demonstrates a complete and undetected eavesdropping attack on a quantum key distribution connection, highlighting the need for further security updates on secure communication systems.

    • Ilja Gerhardt
    • , Qin Liu
    •  & Vadim Makarov

  • Article |

    Error correction in quantum computing can be implemented using transversal gates, which in turn rely on the availability of so-called magic states. The authors experimentally show that it is possible to improve the fidelity of these states by distilling five of them into one.

    • Alexandre M. Souza
    • , Jingfu Zhang
    •  & Raymond Laflamme

  • Article |

    Two principles have recently been proposed as attempts to provide physical axioms for quantum mechanics: causality and macroscopic locality. Cavalcanti and colleagues show here that the two are not equivalent, giving confidence in information causality as a constraint for correlations obtained in experiments.

    • Daniel Cavalcanti
    • , Alejo Salles
    •  & Valerio Scarani

Browse broader subjects

Browse Quantum information across other nature.com journals